There are two main types of gas monitors: pumped monitors and diffusion monitors.

Most gas detectors you’ll come across are diffusion monitors. They are designed to work passively, monitoring the gas as and when it comes into contact with the sensor.

Conversely, pumped monitors are equipped with an extension that allows you to target a specific area you want to test the gas levels of and monitor it from a safe distance.

Pumped Monitors are generally seen as more effective since they have a longer reach and, supposedly, a higher level of accuracy.

However, in reality, this isn’t the case.

Yes, a pumped allows for longer reach, but it doesn’t guarantee a higher level of accuracy, as the detector will still only monitor the gases that come into direct contact with its sensor via the extension.

There is also a time factor. You have to allow for the gas to make its way through the pump, so you won’t be getting instantaneous results.

When to use a pumped monitor?

But even if a pump monitor isn’t more effective than a diffuser, it still has its uses.

They are particularly useful when you need to assess a potentially hazardous space before entry.

For workers operating in long or narrow situations without much room to manoeuvre, it’s helpful to be able to extend sample line ahead of you (or below you, if entering vertically) so you can always be conscious of the gas levels you’re heading into.

When to use a diffusion monitor?

Diffusers, meanwhile, are useful for situations where you’re working in a more open area or over a longer period.

As pumped monitors have more components, they will use more power. Many workers in need of gas detectors could be on shift for twelve hours or longer, and need a device that will last throughout their shift.

Diffusion monitors are perfect for these situations.

There’s also the fact that the pump can bulk the device out, meaning it’s more to carry. As diffusion monitors are generally quite compact, they are a much more manageable choice for longer jobs where you don’t need to measure gases at a distance.

Best Practice?

The type of monitor you use will depend on your work environment. If your role dictates you work in a variety of environments, it would be beneficial to have multiple devices available to you that you can take out to each relevant job.

We recommend a mix of the two. The majority of units should be unpumped, to be worn in any areas where you may be exposed, lighter to carry and with better battery time. You then have a small amount for your pre-entry checks to ensure everyone is safe before entering hazardous areas.

Most manufacturers offer both pumped and unpumped versions of their units, meaning no additional training is required to use these units

If you need to expand your arsenal of gas monitors, our expert team will be happy to advise you on what devices are best suited for you and your business.